Vertical lift toggle clamp

ABSTRACT

A toggle clamp with handle link on a first pivot with respect to supporting side plates and a work securing arm with spaced portions thereof, each pivotally mounted through separately located pivotal links connected to pivot through different arcs, to constrain pivotal movements of the arm to a resultant path in a relatively confined area. A control link interconnects said arm link and work securing arm for effecting opening and closing movements of said arm on opening and closing movements of a latch handle upon a latch which is pivotally mounted upon the arm link. A latch plate spans and is secured to arcuate portions of the side plates and is adapted to cooperatively and retainingly receive the latch when in retracted position.

[ Nov. 18, 1975 VERTICAL LIFI TOGGLE CLAMP [76] Inventor: Leland F. Blatt, 31915 Groesbeck Highway, Fraser, Mich. 48026 22 Filed: Mar. 1, 1974 21 Appl. No.: 447,093

[52] US. Cl 269/94; 269/228 [51] Int. Cl. B25B 5/12 [58] Field of Search 269/91-94, 269/228, 321 ME [56] References Cited UNITED STATES PATENTS 668,009 2/1901 Dakin 74/526 X 2,744,552 5/1956 Novick... 269/321 ME 2,972,476 2/1961 Blatt 269/94 3,028,577 4/1962 Strauss... 269/228 X 3,346,929 10/1967 Webb 269/228 3,371,925 3/1968 Blatt et al. 269/91 3,782,712 l/l974 Blatt 269/228 3,792,853 2/1974 Blatt 269/228 3,831,926 8/1974 Sendoykas et al. 269/228 Primary Examiner-Roy Lake Assistant Examiner-Neil Abrams Attorney, Agent, or Firm-Cullen, Settle, Sloman & Cantor [57] ABSTRACT A toggle clamp with handle link on a first pivot with respect to supporting side plates and a work securing arm with spaced portions thereof, each pivotally mounted through separately located pivotal links connected to pivot through different arcs, to constrain pivotal movements of the arm to a resultant path in a relatively confined area. A control link interconnects said arm link and work securing arm for effecting opening and closing movements of said arm on opening and closing movements of a latch handle upon a latch which is pivotally mounted upon the arm link. A latch plate spans and is secured to arcuate portions of the side plates and is adapted to cooperatively and retainingly receive the latch when in retracted position.

1 Claim, 2 Drawing Figures VERTICAL LIFT TOGGLE CLAMP BACKGROUND OF THE INVENTION clamp is applied to automated or moving equipment and may close during the cycle to create some undesirable interference.

Toggle clamps of the general type are known such as in earlier issued US. Pat. No. 3,371,925 dated Mar. 5, 1968.

BRIEF DESCRIPTION OF THE INVENTION The present invention is directed to an improvement of the type of toggle clamp set forth in the above patent and wherein, there is a different arrangement of the clamp control which incorporates a latch and a latch handle with the latch adapted to lock the clamp mechanism in open position when retracted and, further wherein the latch handle is adapted to disengage the latch and to effect forward closing movement of the linkage and consequent closing of the work securing arm with respect to a workpiece on a support.

It is another object to provide an improved vertical lift toggle clamp wherein, due to the use of a pair of spaced pivot links which rotate in different arcs upon operation of the control linkage, the work securing arm is adapted to move in a resultant path during opening and closing movements defined by the respective above arcs of the supporting links, This provides a vertical lift to the clamp arm, particularly advantageous in limited areas.

The present toggle clamp includes a pair of support links for the work securing arm and a control link for the work securing arm operated by a handle link and incorporating a latch pivotally mounted upon the handle link for securing the arm in open position and for controlling closing movements thereof.

These and other objects will be seen from the following specification and claims in conjunction with the appended drawing.

THE DRAWING:

FIG. 1 is a fragmentary side elevational view of the present toggle clamp.

FIG. 2 is a left end elevational view thereof.

It will be understood that the above drawing illustrates merely a preferred embodiment of the invention, and that other embodiments are contemplated within the scope of the claims hereafter set forth.

DETAILED DESCRIPTION OF THE INVENTION Referring to the drawing, the present vertical lift toggle clamp, FIG. 1, includes a pair of upright spaced side plates 11 having corresponding respective laterally directed base plates 13, positioned upon support 15, fragmentarily shown and suitably secured thereto by fasteners. The side plates may be mounted upon the support 15 in any other suitable manner.

The side plates include lower lateral extension 17 and upper lateral extension 19. The handle link 21 of S- shape is guidably interposed between said side plates and intermediate its ends is connected thereto by the transverse pivot bolt 25 with interposed bushing 23 and a suitable lock nut. This is hereafter referred to as the first pivot point.

A first link 27 at one end is projected into slot 29 of the handle link and pivotally connected thereto by the same pivot bolt 25 at said first pivot point.

The generally upright work securing arm 33 is guidably interposed between the lateral extension 17 of the side plates and intermediate its ends has a slotted portion 31 which receives the other end of the first link 27 and is pivotally connected thereto by the pivot pin 35,

hereafter referred to as a second pivot point. A second clevis-type of link 37 at one end is interposed between the lateral extensions 19 of said side plates and pivotally connected thereto by the pivot pin 35, being a third pivot point. The spaced end portions of the second link receive the free one end of the arm 33 which is pivotally secured thereto by the pivot pin 41, being a fourth pivot point.

Control link 43 at one end is pivotally connected to the free end of the handle link 21 as by pivot pin 45 being the fifth pivot point.

The other end of the control link is pivotally connected to the free end of arm 33 at the pivot point 41 which coincides with pivot connection of the second link with said arm.

The stop arm 47 spans a forward portion of the upper extensions 19 of the side plates and is suitably welded thereto to reinforce the assembly and the spacing of said side plates. Adjustable set screw 49 is threaded through arm 47, is adapted to operatively engage the second link 37 limiting movement thereof in one direction. Said screw serves as a prestop as link 37 is positioned in the forward closed position by link 43. When pivot pin 45 drops below center of pivot pins 41 and 25, this preset pressure causes tension, causing link 43 to be maintained against link 27, maintaining the clamp in the closed, locked position, not requiring the clamp arm 33 to have pressure imposed at W to keep the mechanism in this locked position.

The rear edge portions of said side plates are circular as at 51. Transverse latch plate 53 is adjustably mounted on and spans said side plates along said circular edge and suitably secured thereto as desired by the welds 55. The location of the latch plate 53 corresponds to the position wherein, it is desired that the latch be anchored when the clamp is in fully open position.

The bifurcated latch 57 spans an upper end portion of the arm link 21 and is pivotally connected thereto by the pivot pin 59 referred to as the sixth pivot point. An outer portion of the latch is suitably slotted at 58 for operative retaining engagement with latch plate 53 when the latch has been retracted to the dotted line position shown. This corresponds to a release positioning of the work securing arm 33. A latch handle 63 is adjustably anchored to latch 57. For this purpose, there is provided a ball 61 secured to a portion of the latch. The latch handle at one end has a socket portion which is adjustably positioned angularly as desired over and with respect to the ball in any desired angular position throughout and suitably secured thereto as by the welds 65. Thus, the latch handle 63 may be moved forwardly or rearwardly from the position shown in FIG. 1 or may be moved transversely to the desired angle on either side of center before securing in position.

The upper portion of the arm link 21 has a rearwardly directed socket 69 which supports the compression spring 71. The outer end of said compression spring operatively engages the latch normally urging the same in a clockwise direction. Thus, on retraction of the latch handle 63 from the work securing position shown to the dotted line position shown, the latch 57 will snap into interlocking engagement with the latch plate 53. This secures the clamp mechanism including the work securing arm in release position.

OPERATION In operation as shown in FIG. 1, the first arm supporting link 27 moves in an arc A, and the second arm supporting link 37 moves in a different are B The one end of control link 43 moves through the arc C. It is this movement of the control link connected to the work securing arm 33 which defines a resultant vertical noncircular path D of translatory movement of the work securing arm as designated. This is particularly important in confined areas where there is limited space through which the work securing arm can move when it is translated from the solid line position, securing the workpiece W relative to the support, to the dotted line release position shown. In the illustrative embodiment, this release movement may be only 13 or alternately, could be in the range up to 90 as desired. As the handle is moved rearward on the open part of the cycle, the end of the latch plate, finally dropping into latching position and is secured in a no shake position by the force on latch plate angle on contact with a similar angle in the latch. For clamping, initial forward movement of latch handle 63, rotates latch 57 to disengage latch plate 53. Further translation forward to the solid line position moves the arm 33 to workpiece securing position relative to support 15.

I claim:

1. A vertical lift toggle clamp comprising a pair of spaced upright side plates adapted for securing upon a support;

said plates including lower and upper lateral extensions with rear portions'being circular;

a latch plate in a pre-set angular position along and spanning said rear portions and secured thereto;

a handle link guidably interposed between the side plates;

a first pivot between the side plates pivotally mounting the handle link intermediate its ends;

ally connected to said first pivot; I

a work securing arm guidably interposed between the side plate lower extensions and intermediate its ends pivotally connected to the other end of said a second link at one end interposed between the side plate upper extensions and pivotally mounted thereon;

a pivot interconnecting one end of the work securing arm and the other end of the second link;

a control link at one end pivoted to said work secur ing arm at its connection with the second link, and at its other end pivotally connected to one end of the handle link;

a latch overlying the side plates and pivotally connected to said handle link outwardly of the side plates;

said latch having a latch element adapted for securing and retaining registry with said latch plate on a predetermined retraction of said arm link;

spring means interposed between said handle link and latch normally biasing said latch clockwise;

and a handle secured to and projecting from said latch;

forward manual movement of the latch handle disengaging said latch and rotating said arm link and connected control link translating said arm for gripping a workpiece against said support;

said first link defining a first arcuate path of transla-.

tion of said work securing arm, said second link delink and the control link passes dead center said;

prestop causes tension, maintaining the clamp arm in closed and locked position. 

1. A vertical lift toggle clamp comprising a pair of spaced upright side plates adapted for securing upon a support; said plates including lower and upper lateral extensions with rear portions being circular; a latch plate in a pre-set angular position along and spanning said rear portions and secured thereto; a handle link guidably interposed between the side plates; a first pivot between the side plates pivotally mounting the handle link intermediate its ends; a first link between the side plates at one end pivotally connected to said first pivot; a work securing arm guidably interposed between the side plate lower extensions and intermediate its ends pivotally connected to the other end of said first link; a second link at one end interposed between the side plate upper extensions and pivotally mounted thereon; a pivot interconnecting one end of the work securing arm and the other end of the second link; a control link at one end pivoted to said work securing arm at its connection with the second link, and at its other end pivotally connected to one end of the handle link; a latch overlying the side plates and pivotally connected to said handle link outwardly of the side plates; said latch having a latch element adapted for securing and retaining registry with said latch plate on a predetermined retraction of said arm link; spring means interposed between said handle link and latch normally biasing said latch clockwise; and a handle secured to and projecting from said latch; forward manual movement of the latch handle disengaging said latch and rotating said arm link and connected control link translating said arm for gripping a workpiece against said support; said first link defining a first arcuate path of translation of said work securing arm, said second link defining a second arcuate path of translation of said work securing arm causing a constrained resultant path of closing and opening movements of the work securing arm, a stop arm spanning and secured to forward portions of the side plates; and an adjustable set screw projected through said stop arm limiting movement of the second link in one direction by abutment therewith; said set screw functioning as a prestop for said second link, whereby when the pivot between the arm link and the control link Passes dead center said prestop causes tension, maintaining the clamp arm in closed and locked position. 